Conduit outlet box



Sept. .14, 1937. E. J. DILLMAN El AL CONDUIT OUTLET BOX Filed Nov. 20, 1934 mayzzv 6 lNVENTOlgwfl Zia/L 1201mm? Patented Sept. 14, 1937 UNITED STATES PATENT OFFICE CONDUIT OUTLET BOX ration of Michigan I Application November 20, 1934, Serial No. 753,832

3 Claims.

Our invention relates to new and useful improvements in outlets for electrical conduits, and has particular reference to an outlet box for such conduits, which may be readily adapted for use with electric switches or other control apparatus.

An object of our invention is to provide a simple and readily accessible outlet closure which will permit a rapid, safe, electrically perfect connection to be made between an electrical accessory and a power line.

Another object of the invention is to provide an outlet box which is light in weight, yet durable, and one in which the connecting means are fully enclosed and protected from dirt, oil, moisture and other elements which might cause corrosion and impair the electrical efficiency of the equipment with which the device is used.

The invention consists in the improved construction and in the combination and arrangement of parts to be more fully described hereinafter, the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawing, which constitutes part of our disclosure, we have fully and clearly illustrated a preferred embodiment of our invention, in which drawing Fig. 1 is a top plan view of our device with the casing or cover member removed. I

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. 4.

Fig. 3 is a bottom plan view of the device.

Fig. 4 is an end view looking from right to left of Fig. 2.

Fig. 5 is an enlarged fragmentary sectional View taken on line 55 of Fig. 1.

Fig. 6 is an enlarged fragmentary view partly in section taken on line 6-6 of Fig. 5.

Referring now to the drawing by characters of reference, 8 designates a base member, which is preferably made of an electric insulating material, such as hard rubber, bakelite, or other plastic molding material, and is formed with an internally threaded, cylindrical end portion 9, and an oppositely disposed, substantially flat, bull nosed portion I0, and a centrally disposed upstanding substantially circular portion I I, which is provided with a fiat abutment side face I2 and an inset I3.

The fiat portion II) of the base 8, is provided with two vertical passageways I4 and I5, adapted to receive screws or bolts (not shown), so that the device may be readily attached to another device, such as the stack control switch of an oil burner system, or any other device that requires a connection to an electric power line. It will be noted that the passageway I5 terminates within the interior of the device, so that a screw or bolt cannot be inserted therein. or removed without first uncovering the device.

A longitudinally extending recess I6, Fig. 1, having diverging sidewalls I1 and an under cut bottom wall I8, is formed in the upstanding portion I I, of the base member 8, and communicates, at its point of greatest divergence, with the interior of the internally threaded cylindrical portion 9.

Angularly positioned, with reference to the long axis of the device, and molded in the upstanding portion II, of the base member 8, are two rectangular shaped terminal blocks I9 and 20, preferably made of a high conductive hard metallic substance, and formed with an undercut portion 2I, Fig. 5, near their bases which serve as anchor means for said blocks. The blocks I9 and 20 are provided with vertical passageways 22 and 23, which communicate with counterbored passages 24 and 25, which vertically pass through the flat portion ID, of the base 8, and extend into the upstanding portion II of the same member. Set screws 26 are arranged to engage internally threaded passageways 21, Fig. 6, formed near the top of said blocks I9 and 20, at right angles to the vertical passageways 22 and 23. The sidewalls of the blocks I9 and 20 are recessed so that the heads of the set screws 26 may be carried 1 flush with the walls of the blocks. The blocks I9 and 20 are also provided with set screws 28 and 29, Fig. l, which are vertically mounted in threaded passageways formed therein. The top faces of the blocks I9 and 20 are recessed so that the heads of the set screws 28 and 29 may ride flush with the tops of the said blocks.

A round cover member or cap 30, preferably made of the same material as the base 8, is formed with a knurled outer periphery 3I, depending side walls 32, and an interiorly depending centrally disposed round portion 33, Fig. 2, in which is molded an internally threaded, metallic insert 34, which is arranged to engage an externally threaded, centrally disposed, metallic tie rod 35, which is vertically molded into the flat portion I0 of the base 8, and anchored therein by the undercut portion 38.

The lower edges 31 of the depending sidewalls 32, of the cap 30, are smoothly finished, in order to make close contact with the upper face II, of the upstanding portion II, of the base 8, and overhang the latter, somewhat, so that dirt and moisture are less apt to penetrate between the base 8 and cap 30 into the chamber formed between said base and said cap.

To assemble and use the device, it is first preferably fastened, by means of the internally threaded cylindrical portion 9, to the end of the power line conduit, so that the power line leads extend through the recess I6. One of the power line leads is then inserted horizontally under the set screw 28, and the set screw 28 is tightened. The other power line lead is similarly secured in place by the set screw 29.

One of the leads from the switch or other electrical accessory (not shown) is then passed upwardly through the passageway 24 formedin the base 8, and thence through the passageway 22 formed in the block l9, and is tightly secured in place by the set screw 26. The second lead from the switch or other accessory, is then passed upwardly through the passageway 25 formed in the base 8, and thence through the passageway 23 formed in the block 20, and is tightly secured in place by the set screw 26. The base 8 is then secured to the switch or other accessory by means of screws or bolts which are extended through the passageways l4 and i5, care being had that there is proper alignment of the lead wire holes so that the leads do not become pinched or injured. The cover member 30 is then screwed onto the tie rod 35 until the lower edges 31 of the cover 36 abut tightly against the upper face 4! of the round portion II, and the device is ready to operate.

Having described our invention, what we claim and desire to secure by Letters Patent is:

1..A conduit outlet box comprising a hollow base member of cup-like form defining a chamber for the end portionof a lead Wire, a wall of said base member having an aperture therethrough opening into said chamber for admission of the lead wire end portion, a post secured to the inner bottom wall of said chamber, said base member havinga seating surface normal to and surrounding said post, a cover member having an internal socket facing said post, a terminal post secured to said base member adjacent said post and covered by said cover member, means for securing the lead wire entering said chamber to said terminal post, said cover member having a seating surface normal to said first-named post and cooperable with said first-named seating surface, said first-named post and said socket having cooperable means to hold the seating surfaces of said cover member and said base member tightly in engagement with each other upon movement of said surfaces into engagement, and

sion of a lead wire to said terminal post.

2. A conduit outlet box comprising a hollow base member of cup-like form defining a chamber for lead wire end portions, a wall of said positioned in said compartment, means cooperable with said terminal posts to secure the lead wire portions thereto, said cover member having an inwardly opening internally screw-threaded socket rigid with said cover member and facing said threaded post, said cover member having a seating surface normal to said threaded post and concentric with said socket and said post, said 21 surfaces being movable into tight clamping engagement with each other upon threading of said cover member by its rotation onto said threaded post, said base member having apertures aligned with and for admission of lead wires to said terminal posts from external of said base and said cover member, andmeans cooperable with said terminal postsforsecuring thereto the lead wires entering said last-named apertures.

3. In a conduit outlet box, a hollow-.body comprising separable and cooperable base and cover members, means for clamping said members together, said body having an'opening through a wall thereof, a terminal post within said body and closing the inner end of said opening, said post having a longitudinal aperture for receiving a lead wire entering through said opening, a screw threaded into said post and cooperable with said aperture for holding the lead wire tightly in said aperture, said post having in its inner end a longitudinal screw-threaded opening, a screw adjustable in said threaded opening, said body having a second opening through a wall thereof for admission of a lead wire to be secured to said .post by said adjustable screw.

EARNEST J. DILLMAN. FRANK JOHN SOVEY.

said base member having an aperture for admis- 

